Display device

ABSTRACT

A display device includes: an insulating substrate having flexibility and including a bent portion that is bent at 90 degrees or more outside a display area provided with an image display function; and a spacer disposed inside the bent portion and including a curved area around which the bent portion is wrapped and a plane area facing the insulating substrate/ wherein the insulating substrate includes a flat portion adjacent to the bent portion and provided so as to face the plane area.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese applicationJP2015-069491 filed on Mar. 30, 2015, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION 1. Field of the invention

The present invention relates to a display device,

2. Description of the Related Art

In a display device such as an organic electroluminescent (EL) displaydevice, an image may be displayed by controlling a self-emitting elementsuch as an organic light-emitting diode (OLED) using a switching elementsuch as a transistor. A display panel such as an organic EL panel thatdisplays an image may be configured using a flexible substrate, and mayhave a curved shape.

JP 2013-015835 A discloses a flexible display panel including a firstdisplay area, a second display area located on a curved surface, and afolded non-display area.

SUMMARY OFTHE INVENTION

The display device may include a display area and a picture-frame area.Here, when the width of the picture-frame area is narrowed by foldingthe substrate, it is necessary to prevent the disconnection of ,airinglines provided in the picture-frame area.

It is therefore an object of the invention to provide a display devicein which the risk of disconnection is reduced even when a narrowerpicture-frame is achieved by folding a substrate.

A display device according to an aspect of. the invention includes: aninsulating substrate having flexibility and including a bent portionthat is bent at 90 degrees or more outside a display area provided withan image display function; and a spacer disposed inside the bent portionand including a curved area around which the bent portion is wrapped anda plane area facing the insulating substrate, wherein the insulatingsubstrate includes a flat portion adjacent to the bent portion andprovided so as to face the plane area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a display device according to a firstembodiment of the invention.

FIG. 2 is a side view of a display panel according to the firstembodiment of the invention.

FIG. 3 is a plan view of the display panel according to the firstembodiment of the invention.

FIG. 4 is a perspective view of a spacer according to the firstembodiment of the invention.

FIG. 5 is a perspective view of a spacer according to a first modifiedexample.

FIG. 6 is a perspective view of a spacer according to a second modifiedexample.

FIG. 7 is a side view of a display panel according to a secondembodiment of the invention.

FIG. 8 is a perspective view of a spacer according to the secondembodiment of the invention.

FIG. 9 is a side view of a display panel according to a third embodimentof the invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the invention will be described withreference to the drawings. The disclosure is illustrative only.Appropriate modifications that will readily occur to those skilled inthe art and fall within the gist of the invention are of course includedin the scope of the invention. For more clarity of description, thewidth, thickness, shape, and the like of each part may be schematicallyrepresented in the drawings, compared to those in practicing aspects ofthe invention. However, they are illustrative only, and do not limit theinterpretation of the invention. Moreover, in the specification and thedrawings, elements similar to those described in relation to a previousdrawing are denoted by the same reference numerals and signs, and adetailed description may be appropriately omitted.

First Embodiment

FIG. 1 is a perspective view showing a display device 1 according to afirst embodiment of the invention. The display device 1 is composed of adisplay panel 10 fixed inside a frame 2. In FIG. 1, the frame 2 is shownpartly cut away to illustrate the display panel 10 accommodated there n.The display panel 10 is fixed in a state where the edge portions thereofare folded back as will be described later.

FIG. 2 is a side view of the display panel 10 according to the firstembodiment of the invention. The display panel 10 has flexibility, andis composed of a thin film transistor (TFT) substrate 20 as aninsulating substrate, a counter substrate 21 provided on the TFTsubstrate 20 and having flexibility, and a flexible printed circuit(FPC) board 22 connected to an edge portion of the TFT substrate 20.Here, the TFT substrate 20 and the counter substrate 21 may be formed ofpolyimide or the like. A driver integrated circuit (IC) 23 is mounted onthe flexible printed circuit board 22. Other electronic circuits may bemounted on the flexible printed circuit board 22.

The counter substrate 21 is disposed on a viewing side of a display area11 (display portion A), and the TFT substrate 20 is disposed on the sideopposite to the viewing side. The TFT substrate 20 as an insulatingsubstrate and the counter substrate 21 have a bent portion Bi that isbent at 90 degrees or more outside the display area 11 (the displayportion A). If the bent portion B1 is bent at 90 degrees or more, apicture-frame area is narrowed when viewed from the viewing side. Here,the bend angle of the bent portion B1 may be 180 degrees or more In thedisplay panel 10 according to the embodiment, the bent portion B1 has abend angle of 180 degrees.

A spacer 12 that prevents the disconnection of wiring lines in the bentportion B1 is provided inside the bent portion 310 The spacer 12includes a curved area 32 (shown in FIG. 4) that is disposed inside thebent portion B1 and around which the bent portion B1 is wrapped, a firstplane area 31 facing the TFT substrate 20, and a second plane area(shown in FIG. 4). The TFT substrate 20 includes, corresponding to thefirst plane area 31 of the spacer 12, a fiat portion D1 adjacent to thebent portion B1 and provided so as to face the first plane area 31.

In the display panel 10 according to the embodiment, the disconnectionof wiring lines provided in the TFT substrate 20 is prevented bylimiting the curvature radius of the TFT substrate 20 as an insulatingsubstrate with the spacer 12. Moreover, since the spacer 12 includes thefirst plane area 31, the spacer 12 is prevented from causing a shift inits position due to rotation, and also, the flat portion D1 is providedin the TFT substrate 20 and thus the flatness of the display portion. Ais retained.

The TFT substrate 20 as an insulating substrate includes a folded-backportion C1 that is folded back by the bent portion B1 on the side of thedisplay area 11 (the display portion A) opposite to the viewing side.The flexible printed circuit board 22 as an electronic component isprovided on the outer surface of the folded-back portion C1, and thedriver IC 23 as an electronic component is mounted on the outer surfaceof the flexible printed circuit board 22.

The display panel 10 according to the embodiment is provided with thefolded back portion C1 with the bent portion B1 having a bend angle of180 degrees, and thus, the flexible printed. circuit board 22 and anelectronic circuit such as the driver IC 23 can be disposed on the sideof the display area 11 opposite to the viewing side. Therefore, anelectronic component necessary for driving the display device 1 can bedisposed without widening the picture-frame area.

The folded-back portion C1 is bonded at the inner surface thereof onto asurface of the display area (the display portion A) on the side oppositeto the viewing side. In the display panel 10 according to theembodiment, the TFT substrate 20 is bonded using an adhesive 24.

In the display panel 10 according to the embodiment, the folded-backportion C1 is bonded. with the adhesive 24, so that the opening of thebent portion B1 is prevented, and thus that the bend with a curvatureradius defined by the spacer 12 is retained. Therefore, the displaypanel 10 can be easily assembled into the frame 2.

A bent, portion B2, a folded-back portion C2, and a flat portion D2 ofthe display panel 10, which are located on the side opposite to theflexible printed circuit, board 22, have configurations similar to thebent portion B1, the folded-back portion C1, and the fiat portion D1located on the flexible printed circuit board 22 side. In the displaypanel 10 according to the embodiment, a configuration has beenillustrated in which the TFT substrate 20 and the counter substrate 21are folded by providing the spacer 12 at two of edge portions located onthe four sides. However, the bent portion may be provided at one of theedge portions located on the four sides, or may be provided at three ormore edge portions. Moreover, even when the display panel has a shapeother than a quadri lateral, a narrower picture-frame can be achieved,while preventing the disconnection of wiring lines, by providing thebent portion outside the display area 11 and providing the spacer insidethe bent portion.

FIG. 3 is a plan view of the display panel 10 according to the firstembodiment, of the invention FIG. 3 represents the display panel 10before being assembled into the frame 2. The display panel 10 includesthe display area 11 (area surrounded by the broken line in FIG. 3)provided with an image display function. The display area 11 includespixels that emit lights of RGB colors and each of which is controlled.for its light emission by a control signal output from the driver IC 23,so that full-color display is performed. The display panel 10 accordingto the embodiment is an organic ectroluminescent (EL) display panel, andeach of the pixels is composed of an organic light-emitting diode and acontrol transistor. The display panel 10 is not limited to an organic ELdisplay panel, and may be, for example, a quantum dot display panel.

The display panel 10 includes the display portion A including thedisplay area 11, the fiat portions D1 and D2 adjacent to the displayportion A, the bent portion adjacent to the flat portion D1, the bentportion B2 adjacent to the flat portion D2, the folded-back portion C1adjacent to the bent portion B1 and the folded-back portion C2 adjacentto the bent portion B2. In the display panel 10 according to theembodiment, the TFT substrate 20 and the counter substrate 21 are formedto be greater than the display area 11 in the long-side direction, theflexible printed circuit board 22 is provided in an area of the TFTsubstrate 20 outside the display area 11, and in addition, a commonelectrode wiring line and the like are provided in the outside area.Therefore, when the display panel 10 is assembled into the frame 2 whileremaining in the state shown in FIG. 3, the picture-frame area iswidened in the long-side direction. In the display device 1 according,to the embodiment, therefore, the TFT substrate 20 and the countersubstrate 21 are folded to achieve a narrower picture-frame.

FIG. 4 is a perspective view of the spacer 12 according to the firstembodiment of the invention. In the drawing, a border line between thefirst plane area 31 and the curved area 32 and an axis 41 are virtuallyshown. The curved area 32 of the spacer 12 has the shape of a surface ofrevolution obtained by rotating a straight line parallel to the axis 41about the axis 41. The shape of a surface of revolution is the shape ofa surface of a circular cylinder. In the spacer 12 according to theembodiment, the shape of a surface of revolution is a shape obtained byrotating a straight line parallel to the axis 41 at a position of a 0.5mm radius relative to the axis 41. However, the radius of the curvedarea 32 measured from the axis 41 may be a value other than 0.5 mm. Thecurvature radius of the curved area 32 defines the curvature radius ofwiring lines provided in the TFT substrate 20. The curvature radius ofthe curved area 32 is minimized to such an extent that the wiring linesprovided in the TFT substrate 20 are not disconnected, so that thethickness of the display panel 10 can be suppressed.

The first plane area 31 and the second plane area 33 are provided indirections away from the curved area 32 and tangential to an arc 40 thatis drawn by the curved area 32 when the spacer 12 is viewed incross-section in the direction of the axis 41 a. The arc 40 is an arcabout the axis 41. The first plane area 31 and the second plane area 33are plane areas extending in the direction of the axis 41 and in thedirections tangential to the arc 40.

The spacer 12 includes a projecting portion 30 that projects in adirection away from the curved area 32 and tangential to the arc 40. Thefirst plane area 31 and the second plane area 33 are surfaces of theprojecting portion 30. Since the spacer 12 includes the projectingportion 30, even when the TFT substrate 20 as an insulating substratehas flexibility, the spacer 12 is prevented from rotating inside thebent portion and also the insulating substrate is reinforced.

The projecting portion 30 includes the first plane area 31 extendingfrom one end of the arc 40 in the direction tangential to the arc 40,and the second plane area 33 extending from the other end of the arc 40in the direction tangential to the arc 40. The first plane area 31 sprovided. at an angle of 90 degrees or less with respect to the secondplane area 33. In the spacer 12 according to the embodiment, the firstplane area 31 is provided at a right angle, that is, an angle of 90degrees, with respect to the second plane area 33. In this manner, sincethe first plane area 31 and the second plane area 33 are provided at anangle of 90 degrees or less, a plane area having an area sufficient tosupport the insulating substrate is provided on the spacer.

FIG. 5 is a perspective view of a spacer 12 a according to a firstmodified example. The spacer 12 a according to the modified exampleincludes. in the curved area 32, first groove portions 50 that areprovided so as to extend in a direction parallel to the axis 41. Adisplay device according to the modified example has configurationssimilar to those of the display device 1 according to the firstembodiment, excepting that the spacer 12 a includes the first grooveport ions 50. In the example shown in FIG. 5, five first groove portions50 are provided, but the number of first groove portions 50 is notlimited to this example, and it is sufficient that the number thereof isone or more.

The spacer 12 a according to the modified example is bonded to the bentportion B1 with an adhesive member provided. in the first groove portion50. This prevents the spacer 12 a from rotating inside the bent portionB1, and also prevents the spacer 12 a from causing a shift in itsposition. Further, the folded-back state is retained without bonding thefolded-back portion C1 with the adhesive 24.

FIG. 6 is a perspective view of a spacer 12 b according to a secondmodified example. The spacer 12 b according to the modified exampleincludes second groove portions 51 that are provided along an arc thatis drawn by the curved area 32 when the spacer 12 b is viewed incross-section in the direction of the axis 41. A display deviceaccording to the modified example has configurations similar to those ofthe display device 1 according to the first embodiment, excepting thatthe spacer 12 b includes the second groove portions 51. In the exampleshown in FIG. 6, five second groove portions 51 are provided, but thenumber of second groove portions 51 is not limited to this example, andit is sufficient that the number thereof is one or more.

The spacer 12 b according to the modified example is bonded to the bentportion B1 with an adhesive member provided in the second groove portion51. This prevents the spacer 12 b from rotating inside the bent portionB1, and also prevents the spacer 12 a from causing a shift in itsposition. Further, the folded-back state s retained without bonding thefolded-back portion Cl with the adhesive 24.

Second Embodiment

FIG. 7 is a side view of a display and 10 a according to a secondembodiment of the invention. In a spacer 12 c according to theembodiment, the size of a projecting port on 30 a (shown in FIG. 8) isgreater than the projecting portion 30 of the spacer 12 according to thefirst embodiment. As to other configurations, a display device accordingto the second embodiment has configurations similar to those of thedisplay device 1 according to the first embodiment.

The display panel 10 a according to the embodiment includes, in additionto the display port on A, a first flat portion D3, a bent portion B3, asecond flat portion D4, and a folded-back portion C3. Although, in FIG.7, an edge portion of the display panel 10 a on the side where theflexible printed circuit board 22 is provided is illustrated, thedisplay panel 10 a according to the embodiment has similarconfigurations also at an edge portion on the side opposite to the sidewhere the flexible printed circuit board 22 is provided.

The projecting portion 30 a of the spacer 12 c includes a first planearea 31 a and a second plane area 33 a (shown in FIG. 8). A TFTsubstrate 20 a according to the embodiment includes, corresponding tothese plane areas, the first flat portion D3 facing the first plane area31 a and adjacent to the bent portion B3, and the second flat portion D4facing the second plane area 33 a and adjacent to the bent portion B3.

FIG. 8 is a perspective view of the spacer 12 c according to the secondembodiment of the invention. In the drawing, a border line between thefirst plane area 31 a and a curved area 32 a and an axis 41 a arevirtually shown. The curved area 32 a of the spacer 12 c has the shapeof a surface of revolution obtained by rotating a straight line parallelto the axis 41 a about the axis 41 a. The shape of a surface ofrevolution is the shape of a surface of a circular cylinder. In thespacer 12 c according to the embodiment, the shape of a surface ofrevolution is a shape obtained by rotating a straight line parallel tothe axis 41 a at a position of a 0.5 mm radius relative to the axis 41a.However, the radius of the curved area 32 a measured from the axis 41 amay be a value other than 0.5 mm. The curvature radius of the curvedarea 32 a defines the curvature radius of wiring lines provided in theTFT substrate 20 a. The curvature radius of the curved area 32 a isminimized to such an extent that the wiring lines provided in the TFTsubstrate 20 a are not disconnected, so that the thickness of thedisplay panel 10 a can be suppressed.

The first plane area 31 a and the second plane area 33 a are provided indirections away from the curved area 32 a and tangential to an arc 40 athat is drawn by the curved area 32 a when the spacer 12 c is viewed incross-section in the direction of the axis 41 a. The arc 40 a is an arcabout the axis 41 a. The first plane area 31 a and the second plane area33 a are plane areas extending in the direction of the axis 41 a and inthe directions tangential to the arc 40 a.

The spacer 12 c includes a projecting portion 30 a that projects in adirection away from the curved area 32 a and tangential to the arc 40 a.The first plane area 31 a and the second plane area 33 a are surfaces ofthe projecting portion 30 a. Since the spacer 12 c includes theprojecting portion 30 a, even when the TFT substrate 20 a as insulatingsubstrate has flexibility, the spacer 12 a is prevented from rotatinginside the bent portion and also the insulating substrate is reinforced.

The projecting portion 30 a includes the first plane area 31 a extendingfrom one end of the arc 40 a in the direction tangential to the arc 40a, and the second plane area 33 a extending from the other end of thearc 40 a in the direction tangential t.o the arc 40 a. The first planearea 31 a is provided at an angle θ of 90 degrees or less with respectto the second plane area 33 a. In the spacer 12 c according to theembodiment, the first plane area 31 a is provided at the angle θ withrespect to the second plane area 33 a. Here, θ is an angle greater than0 degrees and less than 90 degrees In this manner, since the first planearea 31 a and the second. plane area 33 a are provided at an acuteangle, a plane area having an area sufficient to support. the insulatingsubstrate is provided on the spacer. Moreover, the first flat portion D3is provided in the TFT substrate 20 a due to the first plane area 31 aincluded in the spacer 12 c, so that the TE1 substrate 20 a is firmlysupported even if the TFT substrate 20 a is flexible.

In the curved area 32 a of the spacer 12 c according to the embodiment,a groove portion that is provided so as to extend in a directionparallel to the axis 41 a or a groove portion that is provided along thearc 40 a may be provided.

Third Embodiment

FIG. 9 is a side view of a display panel 10 b according to a third.embodiment of the invention. The display panel 10 b according to theembodiment includes a back plate 25 that is disposed on the side of thedisplay area opposite to the viewing side and at least one edge of whichis interposed in the TFT substrate 20 as an insulating substrate Thedisplay panel 10 b according to the third embodiment has configurationssimilar to those of the display panel 10 according to the firstembodiment, excepting that the back plate 25 is included.

An electronic component for driving a display device may be mounted onthe outer surface of the back plate 25. By mounting the electroniccomponent on the outer surface of the back plate 25, an area of thedisplay area on the side opposite to the viewing side can be utilized.

In the display panel 10 b according to the embodiment, even when the TFTsubstrate 20 and the counter substrate 21 have flexibility, the entiresurface of the display area is strongly reinforced by forming the backplate 25 using a highly rigid material such as metal or polycarbonateresin. Moreover, a display device having a curved display area can berealized by molding the back plate 25 into a three-dimensional shapeincluding a curved surface.

All display devices that may be implemented, based on. the displaydevice 1 described as the embodiment of the invention, by those skilledin the art through appropriate changes in. design also belong to thescope of the invention as long as the display device contains the gistof the invention. For example, the spacer 12 may be formed. integrallywith the frame 2, and the display panel 10 may be fixed so a s to wraparound the spacer 12 formed integrally with the frame 2.

Various altered and modified examples within the range of the idea ofthe invention will occur to those skilled in the art, and it isunderstood that the altered and modified examples also belong to thescope of the invention. For example, when those skilled in the artappropriately add or remove a component or change the design of acomponent in the embodiments described above, or add. or omit a processor change the conditions of a process in the embodiments describedabove, those are included in the scope of the invention as long as theyinclude the gist of the invention.

Moreover, it is understood that as to other operational effects broughtabout by the aspects described in the embodiments, an operational effectthat is apparent from the description of the specification or that willappropriately occur to those skilled in the art is of course broughtabout by the invention.

While there have been described what are at present considered to becertain embodiments of the invention, it will be understood that variousmodifications may be made thereto, and it is intended that the appendedclaim cover all such modifications as fall within the true spirit andscope of the invention.

What is claimed is:
 1. A display device comprising: a flexible substratehaving a first surface and a second surface opposite to the firstsurface, the flexible substrate including a first portion, a secondportion, and a bent portion between the first portion and the secondportion, the bent portion bent at 90 degrees or more; and a display areaon the first surface of the first portion, wherein the bent portionincludes a curved portion the curved portion has an inner diameter on aside of the second surface of the flexible substrate, the first portionand the second portion face each other, and a distance between thesecond surface of the first portion and the second surface of the secondportion at a region where the first portion and the second portion faceeach other is smaller than the inner diameter.
 2. The display deviceaccording to claim 1, further comprising a first spacer in a backside ofthe first portion, wherein the spacer is sandwiched between the secondsurface of the first portion and the second surface of the secondportion.
 3. The display device according to claim 1, further comprisinga second spacer, wherein the second spacer has a curved surface alongthe curved portion, and the curved portion is in contact with the curvedsurface.
 4. The display device according to claim 3, wherein the secondspacer has a projecting portion projecting outward from the curvedsurface, the projecting portion having a first plane portion, and a partof the backside of the first portion is along the first plane portion.5. The display device according to claim 4, wherein the projectingportion has a second plane portion, the first plane portion extends fromone end of the curved surface in a direction tangential to a cylindricalcolumn of the curved surface, the second plane portion extends fromanother end of the curved surface in a direction tangential to thecylindrical column of the curved surface, and the second plane portionis at an angle of 90 degrees or less with respect to the first planeportion.
 6. The display device according to claim 3, wherein the secondspacer has a groove in the curved portion so as to extend in a directionparallel to an axis of a cylindrical column of the curved surface, anadhesive member is in the groove, and the curved portion and the bentportion are bonded with the adhesive member.
 7. The display deviceaccording to claim 3, wherein the second spacer has a groove in thecurved portion so as to extend in a direction perpendicular to an axisof a cylindrical column of the curved surface, an adhesive member is inthe groove, and the curved portion and the bent portion are bonded withthe adhesive member.
 8. The display device according to claim 1, whereinthe bent portion has a bent angle of 180 degrees or more.
 9. The displaydevice according to claim 1, wherein the flexible substrate includes afolded-back portion folded back by the bent portion onto a side oppositeto a viewing side of the display area, and the folded-back portionincludes the second portion and is bonded at an inner surface thereofonto the side.
 10. The display device according to claim 1, wherein theflexible substrate includes an another bent portion, the first portionis between the bent portion and the another bent portion, the flexiblesubstrate includes an another second portion, and the another bentportion is between the first portion and the another second portion. 11.The display device according to claim 1, further comprises a flexibleprinted circuit board, wherein the flexible printed circuit board ismounted on an end part of the flexible substrate.
 12. The display deviceaccording to claim 9, further comprises a flexible printed circuitboard, wherein the flexible printed circuit board is mounted at thefolded-back portion.